How to beat Brock easily
Actually, the easiest way to beat Brock without training your Pokemon so much, is to catch a Mankey. I caught mine in the block of grass just south of Pewter City. When you catch it, it should know Scratch.
However, if you get lucky, you might find one that knows Low Kick. I caught mine at Level 6, and I trained it to Level 10 in the grass and the trainer before Brock.
Since fighting is Super-Effective against rock, it will be easy. You can also catch a NidoranĀČ (NidoranĀČ is the purple one) and then train it to learn Double Kick. That will, however, take a lot of training, and it may have to evolve into a Nidorino first.
Keep in mind that I think Mankey is very rare in that spot south of Pewter City (took me about 20 tries) so catch it the first chance you get. Also, if you are confused, this sign means male (ĀČ) and this means female (Āä).
Added by: ActionReplayFreak Jan 12th 2007, ID#4494